NON-NATIVE PLANTS ON SOUTH GEORGIA Season Report 2018/19
NON-NATIVE PLANTS ON SOUTH GEORGIA Season Report 2018/19
Kelvin Floyd Indigena Biosecurity International
This report was prepared by Indigena Biosecurity International Limited for the Government of South Georgia and the South Sandwich Islands
April 2019
PO Box 54, Nelson, New Zealand. www.indigena.co.nz INTRODUCTION
Non-native plant management during the 2018/19 season focused on undertaking actions to implement the ‘South Georgia Non-Native Plant Management Strategy 2016–2020’. Management action was taken to address priority non-native plant species and high priority sites. Further surveys were carried out to fill gaps in distribution data. There are now 82 non-native plant species recorded from South Georgia. Of these, 35 species are historic and presumed extinct, 3 are widespread and naturalised, and 5 are common locally. There are 36 species (Class One) that are managed on a zero population density basis (i.e. plants which may be present but are controlled before they set seed). Three research species require more information to classify. Although there were fewer temperature extremes in 2018/19 than in the previous season, rainfall was higher. In response to the warm 2017/18 summer some species produced more seedlings than usual this year. Lower than usual seal numbers this year meant some plants normally trampled were visible this season. Lobelia pratiana (berry-lobelia) has now been reclassified as a Class Two species due to the documented increase in its geographical distribution as it recovers from reindeer grazing. A new species (Rumex acetosa) to the island was found near Husvik whaling station and will be formally identified by the Royal Botanical Gardens at Kew..
Non-native plant species classes
Class Description
Class One – Priority species; require species-led control at the island-wide level, to control Species-Led all plants before they reach maturity. All sites with these species have a 'Site Tag' in the Weeds Database to enable management of follow-up visits.
Class Two – Species of moderate distribution, requiring site-led control. Priority Site-Led populations are those at high-use visitor sites, and sites with small infestations where control will reduce further dispersal.
Class Three – Species which are widespread and abundant, and require management at Site-Led high-use visitor sites and at some remote outlier sites where appropriate.
Research More information required before classification.
Non Native Plants on South Georgia Season Report 2018/19 Page 3
WORK UNDERTAKEN THIS SEASON
This season the field team consisted of Kelvin Floyd (team leader), Sally Poncet, Ken Passfield, Jörg Kluge and Pamela Quilodran. Field work for the Darwin Initiative project ‘Securing South Georgia’s native habitats following invasive species control’ was also undertaken in association with non-native work this season by the team. Kelvin and Pamela arrived at King Edward Point(KEP) on FPV Pharos SG on 22rd December and began work locally around the base and Grytviken. Sally and Ken arrived at Husvik on 17th January via the FPV Pharos SG and carried out control of Class One and Two species in the Stromness Bay area including a half day on Grass Island supported by FPV Pharos SG. They returned to KEP on 27th February on a GSGSSI/BAS jet boat then went to Sorling Valley hut the following day to undertake work at Ocean Harbour and Hound Bay, returning to KEP on 4th March. They departed South Georgia on 7th March on FPV Pharos SG. Jörg Kluge joined the team at KEP on 2nd February, arriving on the cruise ship MV Fram . Kelvin, Pame and Jörg undertook work on Thatcher Peninsula near KEP with a short trip to Corral Bay hut to carry out control at Godthul and Reindeer Valley on Barff Peninsula. Kelvin departed on 7th March on FPV Pharos SG. Pame and Jörg departed on 11th March on HMS Clyde.
Summary: 846 square metres of Class One species were treated this year compared to 2,733 square metres last season showing a marked decline in plant coverage at treated sites. 10,976 square metres of Class Two species were treated this season. 26 management units were visited this season for both control and surveys. Rumex acetosa (common sorrel) was found in the Karakatta Valley near Husvik whaling station, a first record for the island. Samples have been sent to Royal Botanic Gardens Kew.
Herbicide usage and species details were recorded daily with all information entered into the South Georgia Plants Database.
Non Native Plants on South Georgia Season Report 2018/19 Page 4
SOUTH GEORGIA NON-NATIVE PLANT STATUS 2017/2018
Species have been classed following the Non-Native Plants Strategy and are separated into each class below with a summary for each species. A full species list is presented at the end of this report
CLASS ONE SPECIES
Each species summary includes a graph showing total plant coverage treated in square metres for each control season.
Class One locations visited 2018/19
Non Native Plants on South Georgia Season Report 2018/19 Page 5
Achillea millefolium yarrow No plants were found at the existing sites this season. Another small site was found near the Husvik whaling station in an area normally trampled by seals. Spread is vegetative as the species is not known to flower or set seed at South Georgia. 25 20 20
20
15
10 Coverage sq m sq Coverage 5 3 1.5 0.08 0.01 0.01 0 0.5 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Achillea ptarmica sneezewort No plants were found at existing sites apart from Husvik whaling station where stem and root fragments are spread during periods of flooding and plants continue to be found in flood areas. Spread is vegetative although in favourable seasons some plants will flower. 350 305 300
250
200
150 126
Coverage sq m sq Coverage 100
50 20.5 13.4 11.2 6 6.7 0 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective but continued vigilance for new fragments required.
Non Native Plants on South Georgia Season Report 2018/19 Page 6
Agrostis stolonifera creeping bent The single site of 200 sq m in Husdal (near Husvik) was followed up this season. Spread is vegetative as the species is not known to flower or set seed at South Georgia.
250 200
200
150
100 Coverage sq m sq Coverage 50 1 0 2017/2018 2018/2019 Season Summary: Control effective.
Agrostis vinealis brown bent Follow-up on all known sites was undertaken. More plants were found this year at sites normally trampled by fur seals (lower seal numbers this season resulted in less damage to vegetation, allowing plants to be more easily detected). Spread is both vegetative and via wind and water-assisted seed dispersal.
600 526.21
500
400 310.85 300 205.61
200 Coverage sq m sq Coverage
100 23.02 0 10 0.25 0 2010/2011 2011/2012 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control is effective on known sites however new sites are still being found.
Non Native Plants on South Georgia Season Report 2018/19 Page 7
Allium schoenoprasum chives Nothing found at the Leith Harbour site this season. Spread is vegetative although the species was occasionally recorded in flower in favourable years.
0.12 0.1
0.1
0.08
0.06
0.04 Coverage sq m sq Coverage
0.02 0 0 0 0 0 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Likely eradicated but site will still continue to be monitored.
Anthoxanthum odoratum sweet vernal grass Sweet vernal grass occurs on the lower slopes of Husdal near Husvik, as well as at some small sites at Maiviken, Grytviken and Sorling. Plants, including outliers continue to be found at the Husdal site. Spread is via wind-assisted seed dispersal.
3500 3010 3000
2500 2001 2000
1500
Coverage sq m sq Coverage 1000
500 118.01 131.1 126.61 0 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control appears effective however seedlings keep appearing.
Non Native Plants on South Georgia Season Report 2018/19 Page 8
Anthriscus sylvestris cow parsley The single site of this species is on the northern side of Nybrakka at Grytviken. Plants found were controlled before they flowered and produced seed; however, this site continues to produce seedlings from the original plant’s seedbank. Two new outliers were found this season up to 50m from the original plants showing the persistence of this species seedbank.
14 12 12
10
8 6 6
Coverage sq m sq Coverage 4
2 1 0.2 0.5 0.25 0.5 0.05 0.35 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective but persistent seedbank.
Cardamine glacialis bittercress Three sweeps of the bittercress sites were completed this season with 4.3 sq m recorded. A new site was discovered across the cove 100m beyond the extent of previously known plants and next to the now disused walking track to the 1982 helicopter crash site. The higher number of seedlings this year is thought to have been due to the previous year’s exceptionally long and favourable growing season. Despite this, the total area controlled was less than last year . Detection of plants obscured by Acaena sp and Poa pratensis is still an issue; a first sweep in early spring before these 2 species have attained maximum growth and before fur seals have trampled plants should be considered.
700 616.62 600
500
400 372.76
300
Coverage sqm Coverage 200
100 29.32 20.84 17.68 10.63 7.8 3.93 4.265 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control on known plants effective but detection of very small adults is an ongoing issue. A early spring control visit should be considered to detect plants before they are obscured by surrounding vegetation.
Non Native Plants on South Georgia Season Report 2018/19 Page 9
Capsella bursa-pastoris shepherd's purse Was among bittercress sites at King Edward Point but not seen for many years. Season Summary: Likely eradicated.
Carex aquatilis water sedge No plants were found at the Husvik whaling station site this season.
250 200
200
150
100 Coverage sq m sq Coverage 50 8 1 1 0.2 0 0.01 0 0 2010/2011 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective although small fragments may continue to appear.
Carex nigra common sedge No plants were found this season. 120 100
100
80
60
40 Coverage sq m sq Coverage
20 10 10 5 1 0 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Non Native Plants on South Georgia Season Report 2018/19 Page 10
Carex sp. sedge species The small patch of Carex species sprayed on the west shore of Block Lake in 2013 has not been found since.
0.12 0.1
0.1
0.08
0.06
0.04 Coverage sq m sq Coverage
0.02 0 0 0 0 0 0 2012/2013 2013/2014 2014/2015 2016/2017 2017/2018 2018/2019 Season Summary: Likely eradicated.
Carex vallis-pulchrae marsh sedge Follow up on this sedge showed good control at the two known sites in Hansen Valley behind Leith Harbour whaling station.
60 50
50
40
30
20 Coverage sqm Coverage
10 1 0 2017/2018 2018/2019 Season Summary: Control effective.
Dactylis glomerata cocksfoot No sign of the single plant controlled in 2010 at Grytviken. Season Summary: Likely eradicated.
Non Native Plants on South Georgia Season Report 2018/19 Page 11
Deschampsia cespitosa tufted hair-grass Previous control has been effective. However, new clumps continue to be found as seeds germinate and flower heads appear above surrounding vegetation in areas trampled by fur seals in previous seasons.
160 150 140
120 111.38
100 85.11 79.1 80 57.05 60 44.8
Coverage sqm Coverage 35 40 25.71 20
0 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective on known plants; however new plants continue to be discovered and there is a persistent seedbank.
Deschampsia flexuosa wavy hair-grass No plants were found this season.
1.2 1
1
0.8
0.6 0.5
0.4 0.3 Coverage sqm Coverage
0.2 0.1 0 0.011 0 0 2011/2012 2012/2013 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective but need to be vigilant for new sites.
Non Native Plants on South Georgia Season Report 2018/19 Page 12
Elytrigia repens couch grass No couch grass has been recorded from known sites at Husvik, Leith and Grytviken since the 2016/17 season. Control appears to have been effective 6 5
5
4
3 2
2 Coverage sqm Coverage
1 0.6 0 0.1 0.1 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Likely eradicated.
Empetrum rubrum diddle-dee The site of the diddle-dee plant at Hestesletten was revisited and no regrowth found. However a small new plant was found on the slopes above Grytviken and controlled. Season Summary: Control effective.
Festuca rubra red fescue Red fescue was treated with glyphosate at all sites this season as previous control with haloxyfop was found to be ineffective. Several new plants were found at Grytviken and King Edward Point. Regrowth also recorded at the Ocean Harbour and Husvik whaling station sites.
300 254
250
200 175
150 100
100 80 Coverage sqm Coverage
50 0 7.1 0 6.1 8.5 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control method changed to glyphosate and now effective. Need to be vigilant for new sites.
Non Native Plants on South Georgia Season Report 2018/19 Page 13
Galium saxatile heath bedstraw No regrowth was found this year at the site found in 2017 next to the walking track near the Maiviken hut.
Season Summary: Control effective.
Holcus lanatus Yorkshire fog No sign of the single plant found in 2017 on Brown Flats terraces opposite King Edward Point.
Season Summary: Control effective.
Juncus filiformis thread rush Regrowth at the Husvik whaling station and Kelp Point sites this season after nothing had been found for the past three seasons.
6 5 5
4 4
3
2 Coverage sq m sq Coverage
1 0.4 0 0 0 0 0 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Leptinella scariosa feathery buttonweed Sites in Hansen Valley were followed up this year. No plants were found at the King Edward Point site.
400 358 350
300
250
200
150
Coverage sqm Coverage 100 50.11 50 13.975 14.38 0 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective however detection is very difficult and new sites are not unexpected. Non Native Plants on South Georgia Season Report 2018/19 Page 14
Luzula multiflora var congesta heath wood-rush Control has been effective although new outliers continue to be found around the Grytviken site; this may be a response to the growing conditions last season.
0.6 0.5
0.5
0.4 0.35
0.3
0.2 Coverage sqm Coverage 0.1 0.1 0.03 0 0 0 0 2011/2012 2012/2013 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective but need to be vigilant for outliers in the disturbed ground at Grytviken.
Nardus stricta mat grass A single clump not in flower was found at the Leith Harbour site, the first to appear since 2015/16.
1.2 1
1
0.8 0.75
0.6
0.4 Coverage sqm Coverage 0.2 0.2 0 0 0.01 0 0 0.01 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Non Native Plants on South Georgia Season Report 2018/19 Page 15
Ranunculus acris meadow buttercup No plants found this season at the Karrakatta Valley site.
0.25 0.2
0.2
0.15 0.1 0.1
0.1 Coverage sqm Coverage 0.05 0 0 0 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective
Ranunculus repens creeping buttercup A single plant was found at one of the Grytviken sites; no plants found at all other sites at Leith Harbour, Prince Olav and Husvik whaling stations.
30 25.3 25
19 20 14.1 15 11.35
10 Coverage sqm Coverage
5 0.46 0.56 0.21 0.02 0.01 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Non Native Plants on South Georgia Season Report 2018/19 Page 16
Rumex acetosella sheep’s sorrel Follow-up control at all sites was undertaken; flowering plants were present at some sites indicating a possible response to last year’s favourable growing season. Some of the patches on high bluffs above Grytviken were controlled although plants on the highest bluffs will require drone or very specialist rope access.
25000 21503.75
20000
15000
10000 8505.1
7117.5 Coverage sqm Coverage 5000 1103 1975.653 36 900 296.68 95.64 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective. However, the seedbank remains vigorous and continued follow-up is required. New methods will be required on the inaccessible bluffs above Grytviken.
Rumex acetosella sites(circled in red) on cliffs behind Grytviken
Non Native Plants on South Georgia Season Report 2018/19 Page 17
Rumex crispus curled dock No plants were found this season.
2.5 2
2
1.5 1.25
1 Coverage sqm Coverage 0.5 0.1 0 0 0 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Sagina procumbens pearlwort (procumbent) Although previous control is effective, new sites continue to be found in Stromness Bay. Detection of this species is very difficult and the discovery of further sites is likely.
50 44 45 40
35 32.7 30 25 20
Coverage sqm Coverage 15 10 4.11 2.43 5 1.3 0.66 0.4 1.63 1 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective. However, this small plant is very difficult to detect and its distribution outside of the Stromness Bay whaling station perimeters may indicate that Class One control is not feasible. However, control of known sites will continue for the present.
Non Native Plants on South Georgia Season Report 2018/19 Page 18
Scorzoneroides autumnalis Autumn hawkbit Nothing found this year at the site in Karrakatta Valley; however a new site was discovered and controlled near the Grytviken cemetery. 6 5
5
4
3
2 Coverage sqm Coverage
1 0.25 0.2 0.01 0.02 0.04 0.2 0 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective
Stellaria media common chickweed Was among bittercress sites at King Edward Point but not seen for many years. Season Summary: Likely eradicated.
Trifolium repens white clover All known sites were checked with no plants found except at one site at Leith Harbour whaling station where plants which had possibly been obscured by fur seal trampling in previous years were present and in flower; fewer seals this season resulted in reduced trampling pressure, allowing plants to recover.
8 7 7 6
6
5
4 3 3 2 2 Coverage sqm Coverage 2
1 0.25 0 0 0 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective
Tripleurospermum indorum scentless mayweed Scentless mayweed, previously recorded at Grytviken, was not seen this season. Season Summary: Likely eradicated.
Non Native Plants on South Georgia Season Report 2018/19 Page 19
Vaccinium vitis-idaea cowberry No plants found this season at the Husdal and Pintail Peninsula sites.
90 85 80 70
60 60 60 50 40
30 Coverage sqm Coverage 20 10 0.2 0.1 0.001 0 0 0 2010/2011 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective.
Veronica serpyllifolia thyme-leaved speedwell Plants continue to be found (all in flower) and treated at Grytviken. There was an increase in plants found this season, possibly in response to last year’s warmer spring and summer.
9 7.7 8
7
6 5 4
3 Coverage sqm Coverage 2 1.3 0.6 0.405 1 0.06 0.02 0.12 0.08 0.22 0 2010/2011 2011/2012 2012/2013 2013/2014 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019 Season Summary: Control effective, but plants continue to be present due to a persistent seedbank.
Non Native Plants on South Georgia Season Report 2018/19 Page 20
CLASS TWO SPECIES
Tables for each species show square metres treated this season in each management unit.
Class Two control locations in 2018/19
Agrostis capillaris common bent All known sites were treated on Thatcher Peninsula, and outlier control was undertaken in other units. Unit sq m Treated Brown Flats 375.1 Grass Island 1.5 Grytviken 1350 Karrakatta 200 Penguin River 1 Prince Olav Harbour 0.1 Reindeer Valley 10 Total 1937.7
Season Summary: The Grytviken population continues to decrease in size. New herbicide rates and adjuvants were trialled this season to hopefully reduce the follow-up required for this species.
Non Native Plants on South Georgia Season Report 2018/19 Page 21
Deschampsia cf. parvula punkgrass This grass covers large areas in Karrakatta Valley with a few smaller patches at Husvik whaling station, Pintail Peninsula and Kelp Point. Following the cessation of grazing by reindeer in 2013, this wind-dispersed species has the potential to spread rapidly within Stromness Bay, colonising mostly sparsely vegetated open ground. Control at the scale required to achieve eradication is not feasible, it may not be possible to contain this species. Season Summary: Monitoring shows that the adult plants can be controlled however the scale of control and follow-up required is not feasible.
Lobelia pratiana berry-lobelia This species appears to have a much wider distribution than previously documented; recovery from reindeer grazing and possibly more favourable growing conditions have resulted in increasing numbers of sites being found. It is also very difficult to locate unless in flower. Pending additional information on this species’ native versus non-native status, it has been changed from Class One to Class Two. Further surveys and control will continue at selected sites in order to better understand management methods. Season Summary: Changed to Class Two due to increase in known population distribution.
Part of the large area behind Husvik containing Lobelia pratiana
Non Native Plants on South Georgia Season Report 2018/19 Page 22
Poa pratensis smooth meadow grass Control of this species this season was on small outlier populations and around high visitor use sites in Shackleton Valley and at Grytviken and King Edward Point, in order to reduce the risk of further spread. This grass continues to increase in distribution as ecosystems recover from grazing; in a good growing season it dominates other vegetation. Unit sq m Treated Barff Point 18 Brown Flats 820 Corral 513 Fortuna East 32 Grytviken 3850 Husdal 400 Husvik 1200 King Edward Point 1000 Penguin River 2 Prince Olav Harbour 0.25 Reindeer Valley 253 Shackleton Valley 500 Total 8588.25 Season Summary: New herbicide rates and adjuvants were trialled this season to hopefully lesson follow-up required on this species.
Trisetum spicatum spike trisetum This wind-dispersed grass covers very large areas in Stromness Bay, particularly at Karrakatta Valley, Pintail Peninsula, Shackleton Valley and Hansen Valley with outlier patches at Cape Saunders, Husdal, Olsen Valley, Grass Island and Kelp Point. Plants are also present at Brown Flats and Grytviken and a single plant has been recorded at Ocean Harbour on Barff Peninsula. Following the cessation of grazing by reindeer in 2013, this grass has spread rapidly within Stromness Bay where control is not considered feasible. However site-led control at Grytviken and the Brown Flats site remains a priority, with two sweeps carried out this season in order to prevent its spread on Thatcher Peninsula. No new plants were found at Ocean Harbour. Unit sq m treated Brown Flats 0.5 Total 0.5
Season Summary: Control is effective at Brown Flats, Grytviken although seedlings continue to appear.
Non Native Plants on South Georgia Season Report 2018/19 Page 23
CLASS THREE SPECIES
This class consists of Cerastium fontanum (common mouse-ear), Poa annua (annual meadow grass) and Taraxacum officinale (dandelion). These are widespread species especially on the central east coast of South Georgia and large-scale control is not considered feasible. Some control was undertaken at the high-use visitor sites and around buildings at Grytviken and King Edward Cove in order to promote localised recovery of native plant species.
RESEARCH SPECIES
Pernettya pumila Falklands mountainberry
A single patch, in full flower, covering approximately 100 sq m was found at 80m above sea level on a steep north-facing rock and scree slope in Hansen Valley in 2018; a second small flowering patch was found this season in the Husdal Valley behind Husvik station. Further surveys to determine its full distribution were undertaken this season and will continue. More information is being sought from the Kew Royal Botanic Gardens to determine its native versus non-native status. Poa spp. This is an unknown Poa spp. that could possibly be a hybrid between Poa annua and the native tussac Poa flabellata. It has been found in small numbers at widespread sites across the island. More information is being sought from the Kew Royal Botanic Gardens to determine its native versus non-native status. Rumex acetosa common sorrel
Two plants of this previously unrecorded species were found in flower this year in Karrakatta Valley near Husvik whaling station. Samples have been sent to the Kew Royal Botanic Gardens for confirmation of species.
Rumex acetosa Karakaatta valley
Non Native Plants on South Georgia Season Report 2018/19 Page 24
HERBICIDE USAGE THIS SEASON
Herbicide types and amounts used this season. Herbicide Total Used Measure 360 Glyphosate 360g/L ai 555 ml 510 Glyphosate 510g/L ai 2,385 ml Blue Dye 10,705 ml Flexidor 125 2,320 ml Grazon 90 2804 ml Haloxyfop 100 13,514 ml Meturon 204 gm Organosilicone 949 ml Punch Penetrant (MSO) 16,742 ml
VISITOR LANDING SITES
Seventeen visitor landing sites (Peggotty Bluff, Cape Rosa, Fortuna Bay (Whistle Cove), Shackleton Walk, Stromness, Leith Harbour, Husvik, Olsen Beach, Sorling Beach, Godthul, Ocean Harbour, Gold Harbour, Prince Olav Harbour, Prion Island and of course Grytviken, Maiviken and King Edward Point), were visited by the weed team this season. As well as surveys for non-native plants, signs of rats were also looked for with no recent activity detected.
Non Native Plants on South Georgia Season Report 2018/19 Page 25
MONITORING
Monitoring plots have been measured this season to look at vegetation changes following herbicide applications. This monitoring will improve the Standard Operating Procedures for each species, through a review of herbicide rates, timing of application, and resultant efficacy following each monitoring check and discussions within the field team. The Darwin Initiative project ‘Securing South Georgia’s native habitats following invasive species control’ will also be analysing the data from monitoring plots. It will also be quantifying the potential for non-native plant species to disperse into new areas following deglaciation due to climate change and estimating from soil seed bank and germination studies the risk of non-native plant species persisting past 2020 when current control programme ends.
Non Native Plants on South Georgia Season Report 2018/19 Page 26
Photo points Photo points were also established at Grytviken and King Edward Point in 2015 to monitor changes in vegetation following control around the buildings and whaling stations. 17 points are being used for annual photographs to show long-term changes in vegetation.
2015 – Bone Cookery 2019 – showing removal of Poa pratenis and increase of native cover.
2015 – Separator Plant 2019 – showing removal of Poa pratenis also reduction in Taraxacum officinale.
Non Native Plants on South Georgia Season Report 2018/19 Page 27
Herbicide Plots 10m x 10m plots each containing 5 quadrats have been set up and use the same monitoring protocol as the GSGSSI long-term vegetation monitoring programme. These plots have been set up to look at changes following herbicide control. It is too early to see significant results, apart from a reduction in target species. However, herbicide applications have already been adjusted following this season’s visual assessment and discussions amongst the team.
Herbicide plot monitoring sites, locations above and table below
Plot Non Native Species Plot Focus Established Re-surveyed Herbicide efficacy and effect on native PP_1 Poa pratensis community Feb-2017 Feb 2019 Herbicide efficacy and effect on native PP_2 Poa pratensis community Feb-2017 Feb 2019 Herbicide efficacy and effect on native PP_3 Poa pratensis community – Control plot (no treatment) Feb 2019 Herbicide efficacy and effect on native RA_1 Rumex acetosella community Feb-2017 Feb 2019 Herbicide efficacy and effect on native AC_1 Agrostis capillaris community Feb-2017 Feb 2019 Deschampsia cf. Herbicide efficacy and effect on native DP_1 parvula community Feb-2017 Feb 2019 Deschampsia cf. Herbicide efficacy and effect on native DP_2 parvula community Feb-2017 Feb 2019 Deschampsia cf. Herbicide efficacy and effect on native DP_6 parvula community – Control plot (no treatment) Feb 2019 Herbicide efficacy and effect on native TS_3 Trisetum spicatum community Feb-2017 Feb 2019 Herbicide efficacy and effect on native TS_4 Trisetum spicatum community Feb-2017 Feb 2019 Herbicide efficacy and effect on native community – Control plot (no TS_5 Trisetum spicatum treatment)community Feb 2019
Non Native Plants on South Georgia Season Report 2018/19 Page 28
AC 1 – Agrostis capillaris This Grytviken site showed a reduction in Agrostis cover. It is hoped with a change in timing and herbicide rates the follow-up will be reduced.
2017 2019
DP 1 – Deschampsia cf. parvula This Karrakatta site showed good results for control. However, this is a widespread species, and large-scale control is not feasible. Long term this plot will provide information on the seedbank response.
DP 2 – Deschampsia cf. parvula This Karrakatta site showed good results for control. However, this is a widespread species, and large-scale control is not feasible. Long term this plot will provide information on the seedbank response.
2017 2019
DP 6 – Deschampsia cf. parvula Established this season as a control plot to compare no treatment versus treatment.
Non Native Plants on South Georgia Season Report 2018/19 Page 29
PP 1 – Poa pratensis This Grytviken site showed a reduction in Poa cover however it is hoped with a change in timing and herbicide rates the follow-up will be reduced.
PP 2 – Poa pratensis This Grytviken site showed a reduction in Poa cover however it is hoped with a change in timing and herbicide rates the follow-up will be reduced.
2017 2019
PP 3 – Poa pratensis Established this season as a control plot to compare no treatment versus treatment.
RA 1 – Rumex acetosella This Grytviken site showed the seedbank response with a few Rumex seedlings appearing, however, all original plants have not regrown.
2017 2019
TS 3 – Trisetum spicatum This Pintail site showed good results for control. However, this is a widespread species that large-scale control over the Busen area is not feasible, although results and seedbank response over time will assist control strategies on other populations.
Non Native Plants on South Georgia Season Report 2018/19 Page 30
TS 4 – Trisetum spicatum This Pintail Peninsula site has shown good results for control and the plot will indicate longer term the seedbank response. However, this is a widespread species that large-scale control over the Busen area is not feasible, although results over time will inform control on other populations.
2017 2019
TS 5 – Trisetum spicatum Established this season as a control plot to compare no treatment versus treatment.
Non Native Plants on South Georgia Season Report 2018/19 Page 31
Class One Quadrats Further quadrat monitoring of selected Class One species has been set up this season to monitor vegetation recovery following control of non-natives which were growing as a monoculture. A general description of the site along with 1m x 1m quadrat data will be recorded each season. Photos of these sites are also taken to show changes over time.
Class One monitoring sites, locations above and table below.
Plot Non Native Species Plot Focus Established Recovery of native species after herbicide AS-01 Agrostis capillaris control Feb-2018 Recovery of native species after herbicide BB-01 Agrostis vinealis control Feb-2018 Recovery of native species after herbicide DD-01 Empetrum rubrum control Feb-2018 Recovery of native species after herbicide RF-01 Festuca rubra control Feb-2018 Recovery of native species after herbicide SV-01 Anthoxanthum odoratum control Feb-2018 Recovery of native species after herbicide TR-01 Juncus filiformis control Feb-2018 Recovery of native species after herbicide WS-01 Carex aquatilis control Feb-2018 Recovery of native species after herbicide YW-01 Achillea millefolium control Feb-2018
Non Native Plants on South Georgia Season Report 2018/19 Page 32
AS01 – Agrostis stolonifera Quadrat measured at Husvik this season.
BB01 – Agrostis vinealis Quadrat measured at Grytviken this season.
DD01 – Empetrum rubrum Quadrat measured near Grytviken this season.
RF03 – Festuca rubra Quadrat measured at Grytviken this season.
SV01 – Anthoxanthum odoratum Quadrat measured at Husvik this season.
TR01 – Juncus filiformis Quadrat measured at Husvik this season.
WS01 – Carex aquatilis Quadrat measured at Husvik this season. An old image was found showing the original population with this year’s photo has been included below.
Carex aquatilis visible as monoculture in 1999 at The native grass Deschampsia antarctica Husvik; image courtesy Basberg (2004). colonising the former area of Carex aquatilis at Husvik in 2018.
YW01 – Achillea millefolium Quadrat measured at Grytviken this season.
Non Native Plants on South Georgia Season Report 2018/19 Page 33
SEASON SUMMARY
The ‘South Georgia Non-Native Plant Management Strategy 2016–2020’ has key performance targets (KPI). Results are shown in the table below.
Strategy Targets 2018/19 Season Result
All Class One species will be at zero population All Class One species sites controlled density.
At least 75% of Class One species will be In progress eradicated by 2020.
Class Two populations will be surveyed and Continuing mapped.
10,000 square metres (1 hectare) of land containing Class Two species will be controlled 10976 square metres controlled 2018/19 annually.
Class Two non-native plant populations will be Areas controlled above included small outlier reduced in abundance and distribution populations to reduce distribution. annually.
In high visitor traffic areas at King Edward Point and Grytviken, Class Two non-native Follow-up control undertaken this season. plants will be maintained at zero density.
More detailed information will be gathered on 26 management units were visited this season. the distribution of Class Three species to Ongoing as opportunities arise to visit remote inform control decisions at outlying sites. management units.
Issues relating to the origin and source of non- One new species to classify from this season. Two native species will be resolved within 12 species not resolved due to further information months of them being added to the Research required to determine their native/non native Class. status.
Non Native Plants on South Georgia Season Report 2018/19 Page 34
The chart below shows the number of Class One species sites per season that are active (have mature or juvenile plants present at the visit) or not active in that season. The total number of sites has increased each year as new sites are found and receive control.
250
200
150 Not Active 100 Active
50
0 2014/2015 2015/2016 2016/2017 2017/2018 2018/2019
Figure 1: Active Class One species sites per season
Rumex acetosella control above Grtviken
Non Native Plants on South Georgia Season Report 2018/19 Page 35
OUTREACH ACTIVITIES UNDERTAKEN
Date Who Outreach Location Audience Information Shared Additional Notes Activity 2015 Brad Myer Presentation Nelson; Rotary Club Presentation on the non technical aspects for the New members of the South Georgia weed strategy and Rotary Club; Zealand associated activities.
2015 Brad Myer Presentation Nelson; Club Presentation on the technical aspects of for the New Members the South Georgia weed strategy and Ornithologic Zealand associated activities. Pictures of birds al Society
2015 Brad Myer Presentation Nelson; Nelson Presentation on the non technical aspects Forum members are made up of New Biodiversity of the South Georgia weed strategy and institutional players in Zealand Forum associated activities. conservation in Nelson
2015 Brad Myer Presentation Nelson; Clifton A presentation to my kids classes (6 and 8 Sally and Ken also presented to New Terrace year olds) – An introduction to South these classes during their visit to Zealand School – 2 Georgia Nelson classes
2015 Brad Myer Presentation Nelson; Deputy Presentation on the technical aspects of New Director of the South Georgia weed strategy and Zealand DoC and associated activities. about 100 senior DoC officers
2015 Brad Myer Presentation Nelson; Biosecurity Presentation on the technical aspects of Biosecurity Officers from the New Institute of the South Georgia weed strategy and local authorities and Zealand New associated activities. representatives from DoC Zealand – Top of the South branch
2016 GSGSSI Information www.gov.g The general A media article on the award of the http://www.gov.gs/indigena- shared on s public contract to Indigena biosecurity-to-deliver-non- website native-plant-management- project/
2016 GSGSSI Information www.gov.g The general South Georgia Non Native Plant Strategy http://www.gov.gs/docsarchive/e shared on s public 2016-2020 and reports nvironment/#tab-5 website
2016 Brad Myer Received a Nelson Us A card of congratulations from Nick card from Smith, who was the Minister of the NZ Conservation at the time. This was Minister of featured on the Indigena website Conservation
7/10/16 Brad Myer Article in the Nelson and The general A media article on the award of the https://www.stuff.co.nz/nelson- Nelson Mail, available public contract to Indigena mail/news/84936749/local- which was online company-wins-international- published to conservation-contract the STUFF website
2016 and Parent Features the www.kaitia Kaitiaki Features the Nelson Mail article on its https://www.kaitiakirestoration.c Ongoing company – Nelson Mail kirestorati clients and website along with a link to the GSGSSI o.nz/about- Kaitiaki o article on its on.co.nz the general website kaitiaki/news_and_announceme Ngahere website public nts.php along with a link to the GSGSSI website
2016 and Indigena Featured on www.indig The general Generic details about the programme www.indigena.co.nz Ongoing Team Indigena ena.co.nz public Website
24/03/17 Nigel Post on Online Visitors to History, landscape and wildlife of south https://www.cactusoutdoor.co.nz Parkinson Cactus blog Cactus Georgia, some information about the /blog/?dir=DESC&order=created on South clothing work we were doing _time&p=4 Georgia website landscape and wildlife
Non Native Plants on South Georgia Season Report 2018/19 Page 36
Date Who Outreach Location Audience Information Shared Additional Notes Activity July 2017 Brad Presentation Dundee, Internationa Presentation on the technical aspects of Myer/ to the Island Scotland l Conference the South Georgia weed strategy and Kelvin Invasives Attendees associated activities. Brad followed Colin Floyd/ Conference. Clubbe (RBG Kew) who gave a key note Sally address on weeds from a global Poncet/ perspective. Paper to be published in Ken proceedings. Passfield
2017 Brad Field guide Available Visitors to Specific details of ecology and location of Myer/Kelvi to the online and SG, people non-native flora, information about n Floyd introduced on SG who biosecurity and the control strategy flora of SG purchase book
01/03/18 Sally Discussions En route staff Weed work in South Georgia, how to Initial dicussions while on board Poncet with staff on South involve cruise ship passengers in the cruise ship en route between NG Explorer Georgia- 'bioblitzing' for weeds using photographic SG and the Falklands, developed Stanley ID and online recording further with the cruise ship company by Brad and Kelvin
05/03/18 Zac Milner Presentation NG Orion Approximate Life on SG, the work we were carrying 15 minutes long, powerpoint (Cruise ly 100 cruise out, general information about SG native presentation. On cruise ship Ship) ship and non-native flora, necessity of heading to Stanley from SG. passengers biosecurity
July 2018 Ken presentation Stanley, Farmers and Weed work in South Georgia and the 45 minute powerpoint Passfield/ Falkland members of Falklands: methods, weeds controlled presentation Sally Islands the public and the importance of biosecurity Poncet during Farmers Week
01/08/18 Sally Presentation Stanley, Members of Weed work including info about the 45 minute powerpoint Poncet Falkland the public logistics behind fieldwork carried out in presentation Islands South Georgia and the Falklands, and the importance of biosecurity
2018 and Kelvin Online flora Online Users of Details of native and non-native flora Ongoing Floyd guide iNaturalist found on SG including photos and website/app mapped location
18/12/18 Brad Myer Radio Stanley General Brad and Kelvin talked about the SG Broadcast in January 2019 interview on Public of the Weed Programme. Sally discussed her Kelvin Falklands Falkland work in the Falklands Floyd Radio Islands Sally Poncet
21/12/28 Brad Myer Contributed Stanley General Colin Clubbe, Rosemary Newton (Kew) Published in January 2019 to a Public of the and Wayne Dawson (Uo Durham) and newspaper Falkland Brad wrote an article on the Darwin proj article for Islands and SG weed management the Penguin News
3/1/2019 Sally Presentation Enroute to Passengers Weed work in South Georgia and the Poncet SG on board Falklands: methods, weeds controlled Ken the MS Fram and the importance of biosecurity Passfield
Non Native Plants on South Georgia Season Report 2018/19 Page 37
RECOMMENDATIONS FOR NEXT SEASON
Field work is continued as per the ‘South Georgia Non-Native Plant Management Strategy 2016–2020’. A logistical support request is made as part of pre-season planning to use FPV Pharos SG to access Prince Olav whaling station (for Class One and Two control), Salisbury Plain and Rosita Harbour (landing site surveys), Koppen Point in Royal Bay (for survey and Class Two control), Grass Island (for Class One and Two control) and to support the team based at the Husvik Villa in Stromness Bay. Cardamine glacialis control should be started prior to Christmas to ensure seeds aren’t being becoming viable. Also options for a spring visit to do the first check before other plant growth obscures plants should be investigated. Additional time on the island may be required if climate conditions continue to be favourable to early plant growth. Late growth can be required for detection, however, control needs to be done as early as possible. Innovative methods will need to be found to control the Rumex acetosella on the bluffs at Grytviken. Due to the height of the cliffs it is likely that a drone will be required Opportunities to collaborate with citizen science such as the ‘bio blitzing’ project initiated by the vessels MV National Geographic Explorer and MV National Georgraphic Orion should be continued. The monitoring project in collaboration with RBG Kew and the University of Durham will continue next season. This will need to be planned carefully to ensure weed control timings are treated as a priority.
Non Native Plants on South Georgia Season Report 2018/19 Page 38
SOUTH GEORGIA NON-NATIVE PLANT SPECIES 2019
Latin Name Common Name Family Weed Class Achillea millefolium yarrow Asteraceae Class One - Species Led Achillea ptarmica sneezewort Asteraceae Class One - Species Led Aegilops sp goat grass Poaceae Historic Agrostis capillaris common bent Poaceae Class Two - Site Led Agrostis stolonifera creeping bent Poaceae Class One - Species Led Agrostis vinealis brown bent Poaceae Class One - Species Led Alchemilla monticola velvet ladys mantle Rosaceae Historic Allium schoenoprasum chives Amaryllidaceae Class One - Species Led Alopecurus genicularus marsh foxtail Poaceae Historic Anthoxanthum odoratum sweet vernal grass Poaceae Class One - Species Led Anthriscus sylvestris cow parsley Apiaceae Class One - Species Led Artemisia sp. mugwort Asteraceae Historic Avena fatua wild-oat Poaceae Historic Brassica cf. napus rape Brassicaceae Historic Capsella bursa-pastoris shepherd's purse Brassicaceae Class One - Species Led Cardamine glacialis bittercress Brassicaceae Class One - Species Led Carex aquatilis water sedge Cyperaceae Class One - Species Led Carex nigra common sedge Cyperaceae Class One - Species Led Carex sp. sedge unknown (not flowering) Cyperaceae Class One - Species Led Carex vallis-pulchrae marsh sedge Cyperaceae Class One - Species Led Carum carvi caraway Apiaceae Historic Centella sp. centella Apiaceae Historic Cerastium arvense field mouse-ear Caryophyllaceae Historic Cerastium fontanum common mouse-ear Caryophyllaceae Class Three - Site Led Dactylis glomerata cocksfoot Poaceae Class One - Species Led Daucus carota carrot Apiaceae Historic Deschampsia cespitosa tufted hair-grass Poaceae Class One - Species Led Deschampsia flexuosa wavy hair-grass Poaceae Class One - Species Led Deschampsia parvula punk grass Poaceae Class Two - Site Led Elytrigia repens couch grass Poaceae Class One - Species Led Empetrum rubrum diddle dee Ericaceae Class One - Species Led Festuca ovina sheeps fescue Poaceae Historic Festuca rubra red fescue Poaceae Class One - Species Led Galium saxatile heath bedstraw Rubiaceae Class One - Species Led Holcus lanatus Yorkshire fog Poaceae Class One - Species Led Hypericum tetrapterum square-stemmed St Johns-wort Clusiaceae Historic Juncus filiformis thread rush Juncaceae Class One - Species Led Lactuca sp. wild lettuce Asteraceae Historic Lamium purpureum red dead-nettle Lamiaceae Historic Leptinella scariosa feathery buttonweed Asteraceae Class One - Species Led Lobelia pratiana berry lobelia Campanulaceae Class Two - Site Led Lolium multiflorum Italian rye grass Poaceae Historic Lolium temulentum darnel ryegrass Poaceae Historic
Non Native Plants on South Georgia Season Report 2018/19 Page 39
Latin Name Common Name Family Weed Class Lotus corniculatus birds foot trefoil Fabaceae Historic Lupinus sp lupin Fabaceae Historic Luzula multiflora var heath wood-rush Juncaceae Class One - Species Led congesta Matricaria discoidea pineapple weed Asteraceae Historic Nardus stricta mat grass Poaceae Class One - Species Led Pernettya pumila Falklands mountainberry Ericaceae Research Phleum pratense timothy grass Poaceae Historic Pisum sativum pea Fabaceae Historic Plantago sp hoary plantain Plantaginaceae Historic Poa annua annual meadow grass Poaceae Class Three - Site Led Poa pratensis smooth meadow grass Poaceae Class Two - Site Led Poa trivialis rough meadow grass Poaceae Historic Poa unknown(hybrid?) Mutant Poa Poaceae Research Ranunculus acris meadow buttercup Ranunculaceae Class One - Species Led Ranunculus repens creeping buttercup Ranunculaceae Class One - Species Led Raphanus sp. radish Brassicaceae Historic Rorippa islandica Northern yellow-cress Brassicaceae Historic Rumex acetosa common sorrel Polygonaceae Research Rumex acetosella sheeps sorrel Polygonaceae Class One - Species Led Rumex alpinus alpine dock Polygonaceae Historic Rumex crispus curled dock Polygonaceae Class One - Species Led Sagina procumbens pearlwort (procumbent) Caryophyllaceae Class One - Species Led Scorzoneroides autumnalis Autumn hawkbit Asteraceae Class One - Species Led Senecio vulgaris common groundsel Asteraceae Historic Sinapis arvensis charlock Brassicaceae Historic Solanum tuberosum potato Solanaceae Historic Sonchus sp sow thistle Asteraceae Historic Stellaria graminea grass leaf starwort Caryophyllaceae Historic Stellaria media common chickweed Caryophyllaceae Class One - Species Led Taraxacum officinale dandelion Asteraceae Class Three - Site Led Thlaspi arvense field penny-cress Brassicaceae Historic Trifolium hybridum alsike clover Fabaceae Historic Trifolium repens white clover Fabaceae Class One - Species Led Tripleurospermum indorum scentless mayweed Asteraceae Class One - Species Led Trisetum spicatum spike trisetum Poaceae Class Two - Site Led Urtica dioica common nettle Urticaceae Historic Urtica urens annual nettle Urticaceae Historic Vaccinium vitis-idaea cowberry Ericaceae Class One - Species Led Veronica serpyllifolia thyme leaved speedwell Scrophulariaceae Class One - Species Led
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